Gervais Lake
Ramsey County, Minnesota235 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Gervais Lake. Here is what has been measured.
- Eutrophic
- Impaired · Impaired biota (cause unknown)
- 2 aquatic invasives
- 41 ft max depth
Gervais Lake in Ramsey County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 5 ft visibility. Phosphorus: 39 µg/L. Chlorophyll-a (algae): 15.5 µg/L. Maximum depth: 41 ft. Surface area: 235.01 acres.
Minnesota DNR's Targeted Survey on September 7, 2021 caught 0.11 walleye per trap net at Gervais Lake. DNR survey details →
Gervais Lake is a 235-acre productive, nutrient-rich eutrophic lake in Ramsey County, Minnesota with a maximum depth of 41 feet. Overall water quality is declining over recent sampling years. The lake supports 14 documented fish species including black bullhead, black crappie, and bluegill. No public access — the lake is private or restricted. Compared to the 43 other monitored lakes in Ramsey County, Gervais Lake ranks #34 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-23. Methodology: how these readings are compared.
Gervais Lake covers about 240 acres in Ramsey County. The median ice-out date is April 3, which is when the open-water season begins. For a place on the water, look through cabin and lake-house rentals near Gervais Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Gervais Lake is good for
From access and monitoring records, not editorial picks.
- Fishing14 species recorded
- Ice seasonIce-out around Apr 3
- Deep water41 ft surveyed max depth
Swimming conditions
Readings onlyBacteria tested: low
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Based on E. coli testing, Gervais Lake rarely exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 1.1% of 92 samples across 3 seasons.
This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Minnesota’s current beach and health-department advisories before swimming.
Whether Gervais Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Gervais Lake
These are the measurements Minnesota PCA publishes for Gervais Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 5 ft. Phosphorus 39 µg/L. Chlorophyll-a 15.5 µg/L. TSI 56.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 39µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 15.5µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 56 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Gervais Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Gervais Lake typically sits around 50°F at the surface in October. Summer average is about 59°F. Usually warmest in Aug (about 61°F) and coldest in Jan (about 37°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (37°F) to its warmest (61°F).
Typical surface water temperature by month, from 1,332 field readings (2010–2025) via the EPA Water Quality Portal. See the full Gervais Lake water temperature breakdown →
Minnesota DNR's Targeted Survey on September 7, 2021 caught 0.11 walleye per trap net at Gervais Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Gervais Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
12 surveys on file from MN DNR Fisheries. Most recent: 2021-09-07 (Targeted Survey).
12 surveys on file · most recent 2021-09-07 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 62.00 | 2–7 in 2021-09-07 | 0.14 lb |
| Green Sunfish | 9.61 | 4 in 2020-07-13 | 0.06 lb |
| Black Crappie | 9.59 | 5–9 in 2021-09-07 | 0.18 lb |
| Spottail Shiner | 8.71 | ||
| Yellow Perch | 7.41 | 6–7 in 2021-09-07 | 0.13 lb |
| Largemouth Bass | 7.27 | 17 in 2021-09-07 | 0.9 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Bluegill
Green Sunfish
Black Crappie
Yellow Perch
From the 2021-09-07 survey
A targeted survey of nearshore and littoral fish species in Gervais Lake was conducted beginning on September 7th, 2021 by Index of Biological Integrity (IBI) Program Staff. Sampling sites were evenly spaced around the lake and each was sampled by backpack electrofishing and seining with a 50-foot or 15-foot seine,…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Gervais Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — GervaisFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — GervaisFish Stocking History · MN DNR LakeFinder
Lake Details
Max depth
41 ft
Surface area
235 acres
Shoreline
3.3 mi
Littoral zone
39%
Share shallower than 15 ft
Public access
No
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
16 sq mi
HydroLAKES / HydroSHEDS
Elevation
853 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Stays via Stay22
Stays near Gervais Lake
Compare lakeside cabins, hotels, and vacation rentals near Gervais Lake in Ramsey County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Gervais Lake are listed below.
Top-rated places to stay near Gervais Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Minnesota’s top lakes →
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Fish Species
Click a species to see every lake where it is documented.
Fishing Gervais Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Worsening6 years
Phosphorus
Improving-1.41 µg/L/yr6 years
Chlorophyll-a
Worsening+2.19 µg/L/yr6 years
Ice season
Typical ice-out
Apr 3
Earliest Mar 7, 2024 · Latest Apr 30, 2018
Typical ice-in
Dec 4
Earliest Nov 15, 2014 · Latest Dec 20, 2001
Most recent ice-out
Mar 29
2026
60 observations · Minnesota PCA ice records
EPA Impairment Status
Gervais Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life, Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN62-0007-00 · Official waterbody report
Nearby Lakes in Ramsey County
Frequently asked questions about Gervais Lake
Where is Gervais Lake?
- Gervais Lake is a lake in Ramsey County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Gervais Lake?
- Gervais Lake in Ramsey County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 5 ft visibility. Phosphorus: 39 µg/L. Chlorophyll-a (algae): 15.5 µg/L. Maximum depth: 41 ft. Surface area: 235.01 acres.
Is Gervais Lake safe to swim in?
- Based on E. coli testing, Gervais Lake rarely exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 1.1% of 92 samples across 3 seasons. That is a historical summary of past bacteria testing, not a current reading and not a swimming clearance. Bacteria levels can spike quickly after heavy rain, so whether Gervais Lake is safe to swim in today is a call for Minnesota's water agency and the county health department; check their current beach advisories before you swim.
What is the water temperature of Gervais Lake?
- Gervais Lake typically sits around 50°F at the surface in October, from 1,332 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Gervais Lake?
- Gervais Lake has a maximum depth of 41 feet. The lake covers 235.01 acres.
What fish are in Gervais Lake?
- Fish species found in Gervais Lake include black bullhead, black crappie, bluegill, common carp, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, tiger muskellunge, walleye, white sucker, yellow bullhead, yellow perch. Gervais Lake is located in Ramsey County, Minnesota.
What did the DNR fisheries survey find at Gervais Lake?
- Minnesota DNR's Targeted Survey on September 7, 2021 caught 0.11 walleye per trap net at Gervais Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Gervais Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
When does Gervais Lake thaw?
- Gervais Lake typically has ice-out around Apr 3. Ice typically forms around Dec 4. The open water season is approximately 245 days.
Can I fish at Gervais Lake?
- Public access to Gervais Lake is listed as no on the lake record, so confirm before you make the trip. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Gervais Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Ramsey County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Minnesota's cleanest lakes, ranked on agency measurements
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State Parks Near Gervais Lake
Other Lakes in Minnesota
Eutrophic Lakes in Minnesota
Where this data comes from
734 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA734 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 2130 B ~ Nephelometric Method
- Turbidity, Nephelometric Method
- Turbidity by Nephelometry
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate